University of Illinois Urbana-Champaign

Superconducting rotor with self-contained thermal management system

Xiao, Jianqiao

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https://hdl.handle.net/2142/127446

Description

Title
Superconducting rotor with self-contained thermal management system
Author(s)
Xiao, Jianqiao
Issue Date
2024-11-19
Director of Research (if dissertation) or Advisor (if thesis)
Haran, Kiruba S
Doctoral Committee Chair(s)
Haran, Kiruba S
Committee Member(s)
  • Miljkovic, Nenad
  • Ansell, Phillip J
  • Stillwell, Andrew R
Department of Study
Electrical & Computer Eng
Discipline
Electrical & Computer Engr
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
  • superconducting
  • electric machine
  • cryogenic
  • torque tube
Abstract
Superconducting (SC) electric machines can reach incredibly high specific power and are especially desirable for weight-sensitive applications including aircraft electric propulsion. However, thermal management of the cryogenic environment has posed challenges to building practical aerospace SC machines. Traditional cryogenic refrigeration involves boiling liquid cryogen, such as liquid helium and nitrogen, in the rotor. Although rotary unions can transfer cryogen from the stationary reservoir at low rotation speeds, they are unreliable at the several thousand revolutions per minute (rpm) required by aircraft propulsors. Closed-loop cryocoolers with integrated compressors are new options for cryogenic refrigeration because of their independence from liquid transfer. Nevertheless, they deliver only a fraction of the cooling power liquid cryogen does. Therefore, a rotor structure with low thermal leakage is critical for cryogen-free refrigeration. Mechanical strength, thermal management, and electromagnetic circuits should be carefully balanced through multiphysics optimization. High-fidelity models must be developed and integrated. This dissertation describes efforts to design a cryogen-free SC rotor with high-temperature superconducting coils, a spoke-suspended torque coupler, and a rotor-embedded cryocooler. The machine’s thermal, electrical, and mechanical models are derived analytically to show the tradeoffs between machine-specific power and thermal leakage. Experimental setups and plans are also discussed in detail to validate the analytical derivation.
Graduation Semester
2024-12
Type of Resource
Thesis
Handle URL
https://hdl.handle.net/2142/127446
Copyright and License Information
Copyright 2024 Jianqiao Xiao

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